Prognostic value of plasma renin activity in heart failure patients with chronic kidney disease

Effects of sacubitril-valsartan on remodelling, fibrosis and mitochondria in a murine model of isoproterenol-induced left ventricular dysfunction

BACKGROUND

Sacubitril/valsartan has been demonstrated to promote left ventricular (LV) reverse remodelling and improve outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Its molecular and tissue effects have not been fully elucidated yet, due to the paucity of preclinical studies, mostly based on ischaemic models. We aimed to evaluate the effects of sacubitril/valsartan on LV remodelling, myocardial fibrosis and mitochondrial biology in a murine model of non-ischaemic LV dysfunction.

METHODS

Adult transgenic male mice with cardiac-specific hyperaldosteronism (AS mice) received subcutaneous isoproterenol injections to induce LV systolic dysfunction. After 7 days, mice were randomized to a 2-week treatment with saline (ISO-AS n = 15), valsartan (ISO + V n = 12) or sacubitril/valsartan (ISO + S/V n = 12). Echocardiography was performed at baseline, at day 7, and after each of the 2 weeks of treatment. After sacrifice at day 21, histological and immunochemical assays were performed. A control group of AS mice was also obtained (Ctrl-AS n = 8).

RESULTS

Treatment with sacubitril/valsartan, but not with valsartan, induced a significant improvement in LVEF (p = 0.009 vs ISO-AS) and fractional shortening (p = 0.032 vs ISO-AS) after 2- week treatment. In both ISO + V and ISO + S/V groups, a trend toward reduction of the cardiac collagen 1/3 expression ratio was detected. ISO + V and ISO + S/V groups showed a significant recovery of mitochondrial morphology and inner membrane function meant for oxidative phosphorylation.

CONCLUSION

In a murine model of non-ischaemic HF, sacubitril/valsartan proved to have beneficial effects on LV systolic function, and on cardiac energetics, by improving mitochondrial activity.

Effects of Angiotensin 1-7 and Mas Receptor Agonist on Renal System in a Rat Model of Heart Failure

Congestive heart failure (CHF) is often associated with impaired kidney function. Over- activation of the renin-angiotensin-aldosterone system (RAAS) contributes to avid salt/water retention and cardiac hypertrophy in CHF. While the deleterious effects of angiotensin II (Ang II) in CHF are well established, the biological actions of angiotensin 1-7 (Ang 1-7) are not fully characterized. In this study, we assessed the acute effects of Ang 1-7 (0.3, 3, 30 and 300 ng/kg/min, IV) on urinary flow (UF), urinary Na⁺ excretion (UNaV), glomerular filtration rate (GFR) and renal plasma flow )RPF) in rats with CHF induced by the placement of aortocaval fistula. Additionally, the chronic effects of Ang 1-7 (24 µg/kg/h, via intra-peritoneally implanted osmotic minipumps) on kidney function, cardiac hypertrophy and neurohormonal status were studied. Acute infusion of either Ang 1-7 or its agonist, AVE 0991, into sham controls, but not CHF rats, increased UF, UNaV, GFR, RPF and urinary cGMP. In the chronic protocols, untreated CHF rats displayed lower cumulative UF and UNaV than their sham controls. Chronic administration of Ang 1-7 and AVE 0991 exerted significant diuretic, natriuretic and kaliuretic effects in CHF rats, but not in sham controls. Serum creatinine and aldosterone levels were significantly higher in vehicle-treated CHF rats as compared with controls. Treatment with Ang 1-7 and AVE 0991 reduced these parameters to comparable levels observed in sham controls. Notably, chronic administration of Ang 1-7 to CHF rats reduced cardiac hypertrophy. In conclusion, Ang 1-7 exerts beneficial renal and cardiac effects in rats with CHF. Thus, we postulate that ACE2/Ang 1-7 axis represents a compensatory response to over-activity of ACE/AngII/AT1R system characterizing CHF and suggest that Ang 1-7 may be a potential therapeutic agent in this disease state.

Plasma renin activity variation following admission predicts patient outcome in acute decompensated heart failure with reduced and mildly reduced ejection fraction

Plasma renin activity (PRA) level at admission is reported to be a prognostic predictor of acute decompensated heart failure (ADHF) patients. Although PRA is affected during hospitalization by several factors including fluid volume and drug titration, whether the changes in PRA levels during hospitalization (ΔPRA) are associated with prognosis of ADHF patients are largely unknown.

PURPOSE

Investigate the predictive impact of ΔPRA on the prognosis of ADHF patients with reduced ejection fraction (HFrEF) and mildly reduced ejection fraction (HFmrEF).

METHODS

Retrospectively analyzed consecutive 116 HFrEF and HFmrEF patients admitted for ADHF. PRA measurements were acquired at admission and at discharge. The primary outcome was a composite of cardiovascular death and HF re-hospitalization.

RESULTS

Out of 116 patients, 85 had PRA measurements both at admission and at discharge. Compared to admission, PRA level was significantly higher at discharge (0.8 (IQR 0.3-2.2) to 2.8 (IQR 1.0-7.2), p < 0.001). Tertiary groups ranked by PRA level on admission showed trend of poor prognosis in order of high, mid, and low PRA level (p = 0.07). On the contrary, PRA level at discharge significantly differentiated the prognosis and was poor in order of high, low, and mid (p = 0.026). Next, when the participants were divided into tertiary groups ranked by ΔPRA, prognosis worsened in the order of "minimal", "decreasing", and the "increasing" tier. Cubic splines analysis also indicate a similar tendency.

CONCLUSIONS

In ADHF patients with HFrEF and HFmrEF, patients with minimal ΔPRA showed the better prognosis over the those with either increasing or decreasing.

Right Heart Function in Cardiorenal Syndrome

Purpose of Review

Since CRS is critically dependent on right heart function and involved in interorgan crosstalk, assessment and monitoring of both right heart and kidney function are of utmost importance for clinical outcomes. This systematic review aims to comprehensively report on novel diagnostic and therapeutic paradigms that are gaining importance for the clinical management of the growing heart failure population suffering from CRS.

Recent Findings

Cardiorenal syndrome (CRS) in patients with heart failure is associated with poor outcome. Although systemic venous congestion and elevated central venous pressure have been recognized as main contributors to CRS, they are often neglected in clinical practice. The delicate hemodynamic balance in CRS is particularly determined by the respective status of the right heart.

Summary

The consideration of hemodynamic and CRS profiles is advantageous in tailoring treatment for better preservation of renal function. Assessment and monitoring of right heart and renal function by known and emerging tools like renal Doppler ultrasonography or new biomarkers may have direct clinical implications.

Norepinephrine, plasma renin activity and cardiovascular mortality in systolic heart failure

OBJECTIVE

We analysed the circulating levels and prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP), norepinephrine (NE), epinephrine (E), plasma renin activity (PRA) and aldosterone in patients with systolic heart failure (HF) receiving therapies that target the sympathetic system and the renin-angiotensin-aldosterone axis.

METHODS

We retrieved data from consecutive HF outpatients with left ventricular ejection fraction (LVEF) <50% and available neurohormones, evaluated at a tertiary referral centre for HF from 1999 to 2016.

RESULTS

Patients (n=1477) were aged 66±13 years, 75% were men, median LVEF was 32% (IQR 25-38), 77% had LVEF <40% and 44% ischaemic HF. At the time of sampling, 69% were on beta-blockers, 75% on ACE inhibitors/angiotensin receptor blockers and 48% on mineralocorticoid receptor antagonists vs 88%, 87% and 66%, respectively, after therapy optimisation. Median NT-proBNP, NE, E, PRA and aldosterone were 1441 ng/L, 494 ng/L, 30 ng/L, 1.2 ng/mL/hour and 130 ng/dL, respectively. Over a 4.8-year follow-up (2.4-8.2), 376 patients died from cardiovascular causes (26%). NT-proBNP and PRA predicted cardiovascular mortality after adjusting for all other univariable predictors. The risk of cardiovascular death increased by 8% or 7% per each doubling of PRA in 2 models considering therapies at the time of sampling or after therapy optimisation. PRA improved metrics of reclassification and discrimination, and independently predicted outcome even in the LVEF <40% subgroup.

CONCLUSIONS

In patients with HF with LVEF <50% or <40%, PRA shows independent prognostic significance from a model that includes NT-proBNP, and might represent an additive tool for risk stratification.

Renin profiling predicts neurohormonal response to sacubitril/valsartan

AIMS

Clinical trials and observational cohorts show that beneficial effects of sacubitril/valsartan are less strong in an appreciable proportion of patients with heart failure with reduced ejection fraction (HFrEF). Lower blood pressure and impaired renal function predict suboptimal sacubitril/valsartan titration and a less favourable response. Circulating renin encompasses neurohormonal activation, intravascular volume, and renal function. We hypothesized that renin may predict response to sacubitril/valsartan, assessed by changes in N-terminal fraction of pro-brain natriuretic peptide (NT-proBNP).

METHODS AND RESULTS

We performed a prospective, open-label, real-life cohort study. The study population consisted of 80 consecutive HFrEF patients (age 66 ± 10 years, 83% men) planned to initiate sacubitril/valsartan. Clinical and biohumoral assessment, including a full neurohormonal panel, was performed at baseline and at 1, 3, and 6 month follow-up. Response to sacubitril/valsartan was defined as ≥30% reduction in NT-proBNP levels from baseline to 6 months. Patients in the lower renin tertile had higher blood pressure and plasma sodium concentration (all P < 0.05). At follow-up, 38 patients (48%) were classified as responders. Circulating renin was lower in the responder group compared with non-responders (19.8 mU/L, IQR 3.7-78.0 mU/L vs. 55.0 mU/L, IQR 16.4-483.1 mU/L; P = 0.004). After adjustment for age, renal function, and blood pressure, renin was independently associated to response to sacubitril/valsartan (P = 0.018).

CONCLUSIONS

In our preliminary study, we show that circulating renin predicts reduction in NT-proBNP levels after sacubitril/valsartan initiation in HFrEF patients. Renin assessment might be useful to discriminate potential responders from the subgroup with a weaker expected benefit, thus needing a closer, tailored management strategy.

Prognostic models for chronic kidney disease: a systematic review and external validation

BACKGROUND

Accurate risk prediction is needed in order to provide personalized healthcare for chronic kidney disease (CKD) patients. An overload of prognosis studies is being published, ranging from individual biomarker studies to full prediction studies. We aim to systematically appraise published prognosis studies investigating multiple biomarkers and their role in risk predictions. Our primary objective was to investigate if the prognostic models that are reported in the literature were of sufficient quality and to externally validate them.

METHODS

We undertook a systematic review and appraised the quality of studies reporting multivariable prognosis models for end-stage renal disease (ESRD), cardiovascular (CV) events and mortality in CKD patients. We subsequently externally validated these models in a randomized trial that included patients from a broad CKD population.

RESULTS

We identified 91 papers describing 36 multivariable models for prognosis of ESRD, 50 for CV events, 46 for mortality and 17 for a composite outcome. Most studies were deemed of moderate quality. Moreover, they often adopted different definitions for the primary outcome and rarely reported full model equations (21% of the included studies). External validation was performed in the Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of Nurse Practitioners trial (n = 788, with 160 events for ESRD, 79 for CV and 102 for mortality). The 24 models that reported full model equations showed a great variability in their performance, although calibration remained fairly adequate for most models, except when predicting mortality (calibration slope >1.5).

CONCLUSIONS

This review shows that there is an abundance of multivariable prognosis models for the CKD population. Most studies were considered of moderate quality, and they were reported and analysed in such a manner that their results cannot directly be used in follow-up research or in clinical practice.

Sympathetic and renin-angiotensin-aldosterone system activation in heart failure with preserved, mid-range and reduced ejection fraction

BACKGROUND

Evidence of sympathetic and renin-angiotensin-aldosterone system activation provided a rationale for neurohormonal antagonism in heart failure with reduced ejection fraction (HFrEF), while no data are available in patients with milder degree of systolic dysfunction. We aimed to investigate neurohormonal function in HF with preserved and mid-range EF (HFpEF/HFmrEF).

METHODS

Three cohorts (n = 189/each) of stable HFpEF, HFmrEF and HFrEF patients were selected (median age 70, 67 and 67 years; male 56%, 73% and 74%, respectively). Patients received a baseline clinical assessment including plasma renin activity (PRA), aldosterone, catecholamines, and N-terminal fraction of pro-B-type natriuretic peptide (NT-proBNP) assays, and were followed-up for all-cause death.

RESULTS

Neuroendocrine profile was similar between HFpEF and HFmrEF, while all neurohormones except epinephrine were higher in HFrEF than in HFmrEF (NT-proBNP 2332 ng/L, IQR 995-5666 vs 575 ng/L, 205-1714; PRA 1.7 ng/mL/h, 0.4-5.6 vs 0.6 ng/mL/h, 0.2-2.6; aldosterone 153 ng/L, 85-246 vs 113 ng/L, 72-177; norepinephrine 517 ng/L, 343-844 vs 430 ng/L, 259-624; all p < 0.001, epinephrine 31 ng/L, 10-63 vs 25 ng/L, 10-44; p = 0.319). These findings were unrelated to treatment heterogeneity. Ten percent of HFpEF patients had elevated PRA, aldosterone and norepinephrine vs. 8% in HFmrEF and 21% in HFrEF. During a 5-year follow-up, survival decreased with the number of neurohormones elevated (HFpEF: log-rank 7.8, p = 0.048; HFmrEF: log-rank 11.8, p = 0.008; HFrEF: log-rank 8.1, p = 0.044).

CONCLUSIONS

Neurohormonal activation is present only in a subset of patients with HFpEF and HFmrEF, and may hold clinical significance. Neurohormonal antagonism may be useful in selected HFpEF/HFmrEF population.

Fibroblast growth factor 23 and tubular sodium handling in young patients with incipient chronic kidney disease

Background

Experimental studies have shown fibroblast growth factor 23 (FGF23)-mediated upregulation of the distal tubule sodium/chloride (Na+Cl−) co-transporter leading to increased Na reabsorption, volume expansion and hypertension. However, data on the associations of FGF23 with renal Na regulation and blood pressure (BP) are lacking in young CKD patients.

Methods

FGF23 and other determinants of mineral metabolism, plasma renin activity (PRA), fractional excretion of Na (FENa) and BP, were analyzed at a single center in 60 patients aged 5–22 years with CKD Stages 1 (n = 33) and Stages 2–3 (n = 27) defined by cystatin C- and creatinine-based estimating equations (estimated glomerular filtration rate, eGFR). Associations between FGF23 and renal Na handling were explored by regression analysis.

Results

Median FGF23 levels were higher in CKD Stages 2–3 versus CKD 1 (119 versus 79 RU/mL; P < 0.05), with hyperparathyroidism [parathyroid hormone (PTH) >69 pg/mL] in only few subjects with CKD Stages 2–3. Median FENa was comparable in both subgroups, but with proportionally more values above the reference mean (0.55%) in CKD Stages 2–3 and 3-fold higher (1.6%) in CKD Stage 3. PRA was higher in CKD Stages 2–3 (P < 0.05). Meanwhile in CKD Stage 1, FGF23 did not associate with FENa, and in CKD Stages 2–3 FGF23 associated positively with FENa (r = 0.4; P < 0.05) and PTH (r = 0.45; P < 0.05), and FENa associated with FE of phosphate (r = 0.6; P < 0.005). Neither FGF23 nor FENa was associated with systolic or diastolic BP in either subgroup. The negative association of eGFR by cystatin with FENa remained the strongest predictor of FENa by multivariable linear regression in CKD Stages 2–3.

Conclusions

The elevated FGF23, FENa and PRA and the positive association of FGF23 with FENa do not suggest FGF23-mediated increased tubular Na reabsorption and volume expansion as causing hypertension in young patients with incipient CKD.

Renin Activity in Heart Failure with Reduced Systolic Function-New Insights

Regardless of the cause, symptomatic heart failure (HF) with reduced ejection fraction (rEF) is characterized by pathological activation of the renin–angiotensin–aldosterone system (RAAS) with sodium retention and extracellular fluid expansion (edema). Here, we review the role of active renin, a crucial, upstream enzymatic regulator of the RAAS, as a prognostic and diagnostic plasma biomarker of heart failure with reduced ejection fraction (HFrEF) progression; we also discuss its potential as a pharmacological bio-target in HF therapy. Clinical and experimental studies indicate that plasma renin activity is elevated with symptomatic HFrEF with edema in patients, as well as in companion animals and experimental models of HF. Plasma renin activity levels are also reported to be elevated in patients and animals with rEF before the development of symptomatic HF. Modulation of renin activity in experimental HF significantly reduces edema formation and the progression of systolic dysfunction and improves survival. Thus, specific assessment and targeting of elevated renin activity may enhance diagnostic and therapeutic precision to improve outcomes in appropriate patients with HFrEF.

NT-proBNP prognostic value is maintained in elderly and very elderly patients with chronic systolic heart failure

BACKGROUND

Circulating concentrations of N-terminal fragment of the prohormone of brain natriuretic peptide (NT-proBNP) are influenced by age and common age-related comorbidities, such as renal dysfunction. Therefore, utility of NT-proBNP for prediction of prognosis in the aged has been questioned. We aimed to investigate the prognostic value of NT-proBNP across age classes in a cohort of patients with chronic systolic HF.

METHODS AND RESULTS

We enrolled 2364 consecutive outpatients with HF and left ventricular ejection fraction ≤50%. Patients were classified according to age quartiles, and a very elderly subgroup was identified, aged ≥85 years. After baseline assessment (including NT-proBNP testing), patients were followed-up for the composite of cardiovascular death, heart transplantation or ventricular assistance device implantation (primary outcome) and for all-cause death (secondary outcome). Patients in the fourth quartile (Q4, age ≥ 77 years, n = 638) and in the very elderly subgroup (age ≥ 85 years, n = 153), had higher NT-proBNP (p < .001 vs Q1). NT-proBNP was independently associated with primary and secondary outcome at 1- and 5-years follow-up in the whole population, as well as in Q4 and in the very elderly subgroup (all p < .05). Compared to the whole population, Q4 and very elderly had higher NT-proBNP cut-off for prediction of 1-year primary (4188 and 9729 ng/l, respectively vs 3710 ng/l) and secondary outcome (4296 and 7634 ng/l, respectively vs 3056 ng/l).

CONCLUSIONS

NT-proBNP predicts mortality in elderly and very elderly patients with chronic systolic HF, both at mid- and long-term follow-up. Higher NT-proBNP prognostic cut-off should be considered in the aged HF population.

Fibroblast growth factor 23 is related to profiles indicating volume overload, poor therapy optimization and prognosis in patients with new-onset and worsening heart failure

BACKGROUND

Fibroblast growth factor (FGF) 23 is a hormone that increases urinary phosphate excretion and regulates renal sodium reabsorption and plasma volume. We studied the role of plasma FGF23 in therapy optimization and outcomes in patients with new-onset and worsening heart failure (HF).

METHODS

We measured plasma C-terminal FGF23 levels at baseline in 2399 of the 2516 patients included in the BIOlogy Study to Tailored Treatment in Chronic HF (BIOSTAT-CHF) trial. The association between FGF23 and outcome was evaluated by Cox regression analysis adjusted for potential confounders.

RESULTS

Median FGF23 was 218.0 [IQR: 117.1-579.3] RU/ml; patients with higher FGF23 levels had a worse NYHA class, more signs of congestion, and were less likely to use an ACE-inhibitor (ACEi) or angiotensin receptor blocker (ARBs) at baseline (all P<0.01). Higher FGF23 levels were independently associated with higher BNP, lower eGFR, the presence of oedema and atrial fibrillation (all P<0.001). In addition, higher FGF23 was independently associated with impaired uptitration of ACEi/ARBs after 3months, but not of beta-blockers. In multivariable Cox regression analysis, FGF23 was independently associated with all-cause mortality (hazard ratio: 1.17 (1.09-1.26) per log increase, P<0.001), and the combined endpoint of all-cause mortality and HF hospitalization (1.15 (1.08-1.22) per log increase, P<0.001).

CONCLUSIONS

In patients with new-onset and worsening HF, higher plasma FGF23 levels were independently associated with volume overload, less successful uptitration of ACEi/ARBs and an increased risk of all-cause mortality and HF hospitalization.

The search for efficient diagnostic and prognostic biomarkers of heart failure

Several biomarkers have been tested for screening, diagnosis and prognosis purposes, as well as to guide treatment in heart failure, but only the assay of circulating B-type natriuretic peptides has widely recognized applications for clinical decision-making. Natriuretic peptides are sensitive in detecting the clinically overt or subclinical myocardial damage, but their plasma levels are increased following every generic insult to the cardiovascular system. Novel biomarkers are required to identify specific pathways of disease progression, such as diverse neurohormonal axes activation, inflammation and fibrogenesis, and to act as a tool for therapeutic tailoring. In this view, Gal-3 and ST-2 assays seem very promising, given their involvement in mechanisms of cardiac fibrosis and their prognostic value.

Renal function on admission modifies prognostic impact of diuretics in acute heart failure: a propensity score matched and interaction analysis

Although intravenous diuretics have been mainstay drugs in patients with acute heart failure (AHF), they have been suggested to have some deleterious effects on prognosis. We postulated that renal function may modify their deleterious effects in AHF patients. The study population consisted of 1094 AHF patients from three hospitals. Renal dysfunction (RD) was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² on admission, and the cohort was divided into a high-dose furosemide (≥100 mg/48 h) and low-dose furosemide group according to the amount of intravenous furosemide used within 48 h from admission. In the whole cohort, in-hospital mortality rate was higher in the high-dose furosemide group than the low-dose furosemide group (12.5 vs. 6.6 %, respectively, P = 0.001). However, this difference in the in-hospital mortality rates was significant only in the RD subgroup (15.6 vs. 7.0 %, respectively, P < 0.001), and not in the non-RD subgroup (2.5 vs. 5.9 %, respectively, P = 0.384). Propensity score-matched analysis was performed to evaluate the impact of high-dose furosemide on prognosis. After propensity score matching, high-dose furosemide was not associated with in-hospital mortality (OR 1.25, 95 % CI 0.73-2.16, P = 0.408). However, there was a qualitative difference in OR for in-hospital mortality between AHF with RD (OR 1.77, 95 % CI 0.96-3.28, P = 0.068) and without RD (OR 0.23, 95 % CI 0.05-1.10, P = 0.064), and there was a significant interaction between eGFR and prognostic impact of high-dose furosemide (P for OR interaction = 0.013). An inverse relationship was observed between eGFR and OR for in-hospital death in the group treated with high-dose furosemide (decreasing OR with better eGFR). The deleterious effect of diuretics was significantly modified with renal function in AHF. This association may be one reason for poorer prognosis of AHF patients complicated with renal impairment.

Biomarkers of Heart Failure with Preserved and Reduced Ejection Fraction

Biomarkers are increaingly being used in the management of heart failure not only for the purpose of screening, diagnosis, and risk stratification, but also as a guide to evaluate the response to treatment in the individual patient and as an entry criterion and/or a surrogate marker of efficacy in clinical trials testing novel drugs. In this chapter, we review the role of established biomarkers for heart failure management, according to the main classification of HF phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with reduced (<40%), preserved (≥50%), and, as recently proposed, mid-range (40-49%) ejection fraction.

Usefulness of High-Sensitive Troponin Elevation After Effort Stress to Unveil Vulnerable Myocardium in Patients With Heart Failure

Elevation of resting high-sensitivity troponin (hs-Tn) holds prognostic value in heart failure (HF), but its pathophysiological meaning is unclear. We aimed to investigate hs-Tn elevation after maximal exercise in patients with systolic HF and its neurohormonal and hemodynamic correlates: 30 patients diagnosed with systolic HF (left ventricular ejection fraction 32 ± 8%, mean ± SD), on guideline-directed medical therapy and not recognized inducible ischemia, underwent maximal cardiopulmonary stress test, with assay of plasma N-terminal proB-type natriuretic peptide (NT-proBNP), norepinephrine (NE), and hs-TnT (hs-TnT) at baseline, peak, and 1 and 4 hours after exercise. Cardiac output (CO) was measured during effort, with a rebreathing technique. The natural logarithm of the ratio between percentage (%) increase in CO and NT-proBNP (ln[CO%/NT-proBNP% increase]) was evaluated, as a noninvasive estimate of Frank-Starling adaptation to effort, with NT-proBNP variation considered as a surrogate of end-diastolic left ventricular pressure variation. Hs-TnT increased during exercise with a 4-hour peak (p = 0.001); 10 patients had hs-TnT increase >20%. Patients with Hs-TnT increase >20% were more symptomatic at rest (p = 0.039) and showed greater NE at peak exercise (p = 0.003) and less ln[CO%/NT-proBNP% increase] (p = 0.034). A lower ln[CO%/NT-proBNP% increase] correlated with greater NE at peak exercise (r = -0.430, p = 0.018). In conclusion, acute troponin elevation after maximal exercise was detected in 1/3 of this series. The association of troponin release with NE, CO, and NT-proBNP changes after effort suggests a pathophysiological link among transient hemodynamic overload, adrenergic activation, and myocardial cell damage, likely identifying a clinical subset at greater risk for HF progression.

Biomarkers of activation of renin-angiotensin-aldosterone system in heart failure: how useful, how feasible?

Renin-angiotensin-aldosterone system (RAAS), participated by kidney, liver, vascular endothelium, and adrenal cortex, and counter-regulated by cardiac endocrine function, is a complex endocrine system regulating systemic functions, such as body salt and water homeostasis and vasomotion, in order to allow the accomplishment of physiological tasks, such as orthostasis, physical and emotional stimuli, and to react towards the hemorrhagic insult, in tight conjunction with other neurohormonal axes, namely the sympathetic nervous system, the endothelin and vasopressin systems. The systemic as well as the tissue RAAS are also dedicated to promote tissue remodeling, particularly relevant after damage, when chronic activation may configure as a maladaptive response, leading to fibrosis, hypertrophy and apoptosis, and organ dysfunction. RAAS activation is a fingerprint of systemic arterial hypertension, kidney dysfunction, vascular atherosclerotic disease, and is definitely an hallmark of heart failure, which rapidly shifts from organ disease to a disorder of neurohormonal regulatory systems. Chronic RAAS activation is an indirect or direct target of most effective pharmacological treatments in heart failure, such as beta-blockers, inhibitors of angiotensin converting enzyme, angiotensin receptor blockers, direct renin inhibitors, and mineralocorticoid receptor blockers. Biomarkers of RAAS activation are available, with different feasibility and accuracy, such as plasma renin activity, renin, angiotensin II, and aldosterone, which all accompany the increasing clinical severity of heart failure disease, and are well recognized prognostic factors, even in patients with optimal therapy. Polymorphisms influencing the expression and activity of RAAS pathways have been recognized as clinically relevant biomarkers, likely influencing either the individual clinical phenotype, or the response to drugs. This solid, growing evidence strongly suggests the rationale for the use of biomarkers of the RAAS activation, as a guide to tailor individual therapy in the current practice, and their implementation as a rule-in marker for future trials on novel drugs in the heart failure setting.

Cardiovascular diseases in older patients with osteoporotic hip fracture: prevalence, disturbances in mineral and bone metabolism, and bidirectional links

BACKGROUND

Considerable controversy exists regarding the contribution of mineral/bone metabolism abnormalities to the association between cardiovascular diseases (CVDs) and osteoporotic fractures.

AIMS AND METHODS

To determine the relationships between mineral/bone metabolism biomarkers and CVD in 746 older patients with hip fracture, clinical data were recorded and serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D, calcium, phosphate, magnesium, troponin I, parameters of bone turnover, and renal, liver, and thyroid functions were measured.

RESULTS

CVDs were diagnosed in 472 (63.3%) patients. Vitamin D deficiency was similarly prevalent in patients with (78.0%) and without (82.1%) CVD. The CVD group had significantly higher mean PTH concentrations (7.6 vs 6.0 pmol/L, P < 0.001), a higher prevalence of secondary hyperparathyroidism (SPTH) (PTH > 6.8 pmol/L, 43.0% vs 23.3%, P < 0.001), and excess bone resorption (urinary deoxypyridinoline corrected by creatinine [DPD/Cr] > 7.5 nmol/μmol, 87.9% vs 74.8%, P < 0.001). In multivariate regression analysis, SHPT (odds ratio [OR] 2.6, P = 0.007) and high DPD/Cr (OR 2.8, P = 0.016) were independent indictors of CVD. Compared to those with both PTH and DPD/Cr in the normal range, multivariate-adjusted ORs for the presence of CVD were 17.3 (P = 0.004) in subjects with SHPT and 9.7 (P < 0.001) in patients with high DPD/Cr. CVD was an independent predicator of SHPT (OR 2.8, P = 0.007) and excess DPD/Cr (OR 2.5, P = 0.031). CVD was predictive of postoperative myocardial injury, while SHPT was also an independent predictor of prolonged hospital stay and in-hospital death.

CONCLUSION

SHPT and excess bone resorption are independent pathophysiological mediators underlying the bidirectional associations between CVD and hip fracture, and therefore are important diagnostic and therapeutic targets.